1. Field of the Invention
The present invention relates to a method of controlling or regulating a device that is intended for the application of a liquid or viscous medium onto an opposing surface. The opposing surface may, for example, be the surface of a running material web, particularly paper or cardboard, or the application surface of an operating applicator unit, especially an applicator roll from which the liquid or viscous medium is transferred to such a material web.
2. Description of the Related Art
A generic method is known, for example, from German Patent Document No. DE 30 36 274 C2. This process is performed on an applicator device in which the doctor blade is pressed, by use of a flexible pressure tubing, against the running opposing surface. The doctor blade is mounted on a support beam whose position relative to the opposing surface is adjustable. At the start of an applicator unit's operating cycle, the doctor blade is adjusted by an operator to a predetermined contact pressure against the opposing surface. The adjustment angle of the doctor blade can be selected such that a doctoring surface at the free end of the doctor blade is substantially parallel to the opposing surface. Should the coating application result achieved with this arrangement require a correction in the contact pressure of the doctor blade against the opposing surface, then the "new" doctor blade contact pressure will be adjusted on the basis of a measurement taken from the coating application result. The adjustment is made by changing the position of the support beam relative to the opposing surface and/or by changing the fluid pressure in the flexible pressure tubing. However, the coating application result achieved with the aforementioned known process does not provide fully satisfactory results at high operating speeds.